Moss, 35, has only eight receptions for 88 yards and one touchdown in his first four games with the team. That puts him on pace to finish the 2012 season with 32 receptions for 352 yards and four scores. That type of production would nearly match his 16-game total for 2010, Moss' most recent season in the NFL. Moss played 16 games for three teams that season, finishing with 28 receptions for 393 yards and two touchdowns.

In that context, then, Moss has picked up where he left off. I see a couple potential reasons for the modest production:

Age factor: Moss simply isn't good enough at this stage of his career to command additional playing time and a larger role in the offense. He would be playing nearly every snap if the 49ers thought he could play the way he played as a younger man. Of course, if Moss could perform at that level, the New England Patriots probably would have held onto him. Moss has played between 26 percent and 36 percent of the offensive snaps in each game so far. That includes games with 21, 16, 21 and 22 snaps.

Offensive philosophy: Coach Jim Harbaugh and offensive coordinator Greg Roman brought a power-oriented scheme to the 49ers. San Francisco has used two running backs and two tight ends on a league-high 53 plays this season, according to ESPN Stats & Information. The team's base offense features one back and two tight ends. Those groupings leave room for only one or two wide receivers. The team has better depth at receiver this season. Michael Crabtree and Mario Manningham are younger than Moss. They're going to play. Crabtree is also a tremendous blocker. That adds to his value.

The chart shows the 49ers' pass targets by week. The games against Green Bay (Week 1) and Minnesota (Week 3) show the 49ers are willing to target Moss regularly in some games, but probably not every game.

Smith missed an open Moss on couple throws against Minnesota in Week 3. The two might have a harder time developing a strong rapport while Moss continues to see limited snaps in a run-oriented offense. Keeping Moss fresh could allow him to become more of a factor in specific game plans, including during postseason.